Two problems related to rear air suspension springs have been reported for the 1997 Ford Expedition. The most recently reported issues are listed below.
My 1997 Ford Expedition XLT rear air suspension at times will "lower" to an extremely shallow height. This is most likely to occur overnight; although it does not always happen. In fact, it has been known to occur after the vehicle has been sitting for as little as an hour and a half. On other occasions, the vehicle does not appear to lower at all, even after sitting overnight. The dealership cannot seem to diagnose the problem. Another mechanic believes that the problem is with either the vehicle's computer system, which appears to be signaling the valves on the air bags to release air but not signaling the valves to close at the proper point. He further suggested (either alternatively or perhaps additionally) that the problem might lie with the air compressor which is not properly regulating the release of air from these valves. He discounted any suspicion that this was any type of a leak in either the air bags or air lines, since no leak had been detected by the dealership and since the vehicle did not regularly lower after extended periods of idle time.
Rear air suspension system lifts rear of vehicle twice over the normal height, and bounces violently over normal street and highway surfaces. On occasion vehicle has gone out of control on the shoulder of the street before it could be stopped.